The present invention relates to the design of the runners of intake manifolds between the air-fuel mixture device and the valve ports of an internal combustion engine to improve the performance of the engine.
In the past, intake manifolds have been originally designed for certain conditions, usually relating to a compromise with respect to different engine components with which the intake manifold is to be used, or speed ranges. For example, some large engine manufacturers use the same intake manifold for their full range of engine sizes, even though the engine displacement may substantially double over the range of engine sizes. It is therefore seen, that the intake manifold common to this wide range of engines cannot operate as efficiently with respect to the individual engines as it would if it were specifically designed for such engine. However, the advantages of manufacturing and stocking only a single intake manifold are the advantages of such a system. Even if a single manifold was designed specifically for a single engine, it would operate most efficiently at only one speed. Cars that are used for local travel and low speeds would have different intake manifold requirements than the same cars used for high speed travel, or even for racing at very high engine speeds with respect to providing the most efficient intake manifold runner construction. In general, the higher the engine speed, the larger should be the intake manifold runner through flow cross-sectional area.